This invention relates to fiber-reinforced composite posts for dental and endodontic applications and more particularly to fiber-reinforced composite posts having good bonding properties.
Dental posts must adhere well to other materials, such as other resins or composites, or to living tissue, such as bone. There are a variety of dental posts on the market today, including ceramic, metal and fiber-reinforced composite posts. U.S. Pat. No. 6,439,890 is directed to a fiber-reinforced composite dental post comprising a plurality of frustoconical sections arranged coaxially along the longitudinal axis of the rod. The frustoconical or jagged sections provide a rough surface to promote chemical bonding as well as mechanical anchors, resulting in a better retention of the post.
U.S. Publication No. 20007/0207444 is also directed to a fiber-reinforced dental post containing a central core of fibers embedded in a resin matrix and a sheath surrounding the core, wherein the sheath is free of fibers. The post includes a silane coating to improve the adhesion of the post to the bonding agent when inserting the post into the patient's root.
U.S. Pat. No. 5,797,748 is directed to a dental post having a central core and a sheath surrounding the central core, wherein the central core is made of at least one bunch of fibers and the core is wrapped by a sheath having at least one layer of oriented, isotropic or non-isotropic fibers. The fibers in the core and the fibers in the sheath are embedded in a curable resin. In order to facilitate adhesion of the post with cement, macro-retentions may be created on the surface of the post, particularly by machining and more particularly by turning or slicing. In order to avoid deteriorating the sheath, it must be overmolded with a resin envelope of small thickness, and the macro-retentions are created on the resin envelope.
Thermoplastic materials are generally ductile, but lack adequate bonding to the resin/cement core materials, which are generally made with dimethacrylic monomers. U.S. Pat. No. 7,235,290, which is hereby incorporated by reference, is directed to a method of making a fiber-reinforced composite material with improved bonding. The outer layer of fibers is exposed by dissolving the outer layer of matrix resin that holds the outer layer of fibers. The dissolution step in this process can weaken the interface between the matrix and the outer layer of fibers, affecting the overall strength of the final product.
It is therefore an object of the invention to provide a dental post fabricated of a fiber-reinforced composite material that is able to bond well to other materials, such as resins and composites and also to living tissue, such as bone. It is a further object of the invention to provide a fiber-reinforced composite dental post that exhibits good mechanical properties.